1. Field of the invention
The present invention relates in general to electrode materials, and more particularly, to electrode materials having components comprising metal inclusions no larger than one micron within carbon particles. The invention is also directed to an electrolytic process and a process for fabricating an electrode with an active material having such components.
2. Background Art
As the demand for high output rechargeable batteries continues to grow, scientists are constantly attempting to increase the energy density and cycling life of batteries. In an effort to enhance these two highly desired qualities, researchers have been striving to maximize the benefits of active material in electrode pastes, increase the gravimetric and volumetric capacity of the active material, and optimize the interfacial characteristics of the electrode pastes. Unfortunately, the electrode materials developed up to date have only exhibited some of these desired properties.
In particular, the first generation "modern" rechargeable batteries utilized lithium metal as its primary anode component. While, metallic lithium provides very high capacity values, its instability and poor interfacial characteristics remained problematic. Second generation rechargeable batteries used lithium alloy anodes. While lithium alloy anodes provided some improvement in cycling efficiency and interfacial characteristics, capacity values remain significantly less than that of pure lithium anodes. Moreover, the improvement of electrochemical properties was not sufficient to allow commercialization of the product. Batteries have also been made with carbonaceous insertion materials (e.g. graphite). Such batteries exhibited good cycle life, but relatively low capacity in comparison to lithium and/or lithium alloy materials. Furthermore, experimentation has been done with the use of metal/metal alloy particles within a carbonaceous matrix. Although such carbon metal compounds exhibited acceptable interfacial properties, as well as promising cycling efficiency, their inability to obtain and maintain a desired high volumetric capacity limited their use in electrochemical cells.